An image captured by a single camera or multiple cameras can be converted into an image that is seen from a designated virtual viewpoint (hereinafter referred to as “virtual viewpoint image”). For example, in an image generation method and apparatus thereof represented in Patent Document 1, the image generation method includes capturing an image of the surrounding of an automobile using one or multiple cameras attached to the automobile; generating an image of the automobile model that is texture-mapped (hereinafter referred to as “mapping”) to a space model of a three-dimensional space according to information about this captured image; further detecting a change in a movable member such as a front door of the automobile; displaying the automobile model of the three-dimensional space by changing the position of the virtual viewpoint according to variation of the detected movable member; and displaying the detected movable member under distortion.